The US Justice Department on Friday dropped the charges against Xi Xiaoxing, a physics professor of Temple University and world renowned expert in the field of superconductivity. Xi had been accused of sharing sensitive technology to China. It turned out that the department has made mistakes over the core evidence.

Xi was arrested in May this year and accused of providing China technology for a pocket heater that is prohibited from export. Some physicists later proved that the heater involved in Xi's case is completely different from those banned from export in the US, and Xi's cooperation with China is legitimate.

This is yet another false Chinese spy case. After the misjudged case of Lee Wen Ho in the 1990s, there have been constant false accusations to charge ethnic Chinese scientists, who were involved in research of sensitive technology, with being "spies." The false allegation against Xi was resolved, but he will suffer a great loss to his  career and reputation, which he won't be able to fully recover.

The US is becoming increasingly vigilant toward Chinese spy activities. Given the rise of China and its influence on the strategic landscape, Washington's mentality is understandable. However, after multiple erroneous cases, the US should have realized that it was just too sensitive. Such an emotion without restraint will not only endanger the atmosphere between Beijing and Washington, but will also worsen the racial tension in US society.

Be it prejudice of ideology or the fact that the US itself has conducted too many espionage or secret network operations, public opinion in Washington and the entire US tend to think China is the most aggressive country toward the US in terms of spying. Such a "portrait" is making ordinary Chinese people feel like they are being "flattered" in a strange way, because normally they don't quite believe Chinese intelligence agencies are so capable of driving the US crazy.

The movie Mission: Impossible Rogue Nation has just opened in China. People are asking why China can't make such a film. Chinese producers and directors respond that if they copy the plot to make similar films about Chinese intelligence agents, Chinese audiences will find it "unreal." Because that is not how Chinese intelligence agencies work in people's imagination.

China is not such a villain, and US sense of insecurity has caused its actions to be exaggerated. The US attaches great value to President Xi Jinping's visit, and considers it a valuable chance to solve outstanding problems. But the US should be realistic, and not overstate the issues.